Field of the Invention
This invention relates to an auxiliary liquid, a liquid set, an image recording method and an image recording apparatus.
Description of the Related Art
To date, inkjet recording apparatus have widely been utilized as computer-related output equipment in view of the advantages they provide including low running cost, down-sizing feasibility and easy adaptability to color image recording using a plurality of color inks. In recent years, there has been a demand for image recording apparatus that can output high quality images at high speed regardless of kinds of the recording mediums to be used with them. In order to realize high speed and high quality image output capabilities, image degrading phenomena such as the phenomenon of so-called feathering that is caused by ink spreading along fibers of recording medium need to be suppressed.
As means that can solve the above-identified problem, image recording apparatus employing a transfer system with an intermediate transfer member are known. In an inkjet image recording apparatus employing a transfer system (to be referred to also as transfer type inkjet image recording apparatus hereinafter), an intermediate image is recorded on an intermediate transfer member by inject method. Then, the intermediate image on the intermediate transfer member is dried. Thereafter, a final image is formed on a recording medium as the dried intermediate image is transferred from the intermediate transfer member onto the recording medium. With an image recording method using an image transfer system, high quality images can be recorded at high speed on various recording mediums including recording paper and the problem of feathering that arises when images are directly output on recording mediums at high speed hardly appears.
For an image recording apparatus employing a transfer system to record high quality images on a recording medium, high transfer efficiency is required to the operation of transferring an intermediate image from the intermediate transfer member. How to achieve high transfer efficiency for intermediate images is an important challenge also from the viewpoint of recording high quality images at high speed.
For example, high transfer efficiency can hardly be achieved when there occur instances where part of the intermediate image on the intermediate transfer member is not transferred onto a recording medium and where an intermediate image is internally divided at the time of transfer and only part of the intermediate image is recorded on a recording medium while the remaining part of the intermediate image is left on the intermediate transfer member.
Japanese Patent No. 4,834,300 discloses an inkjet recording apparatus having an auxiliary liquid application unit applying an auxiliary liquid that contains water-soluble resin to the intermediate transfer member of the apparatus as means for improving the efficiency of transferring an intermediate image from the intermediate transfer member. The main purpose of providing such an auxiliary liquid application unit is to improve a scratch resistance of an image. Japanese Patent No. 4,834,300 also discloses application of an auxiliary liquid that contains a water-soluble resin after the formation of an intermediate image in order to assist the mutual adhesion of a recording medium and the intermediate image and consequently improve the transfer performance.